Methods and devices for non-invasively measuring quantitative information of substances in living organisms

• US 20050197555A1
• Filed: 03/06/2005
• Published: 09/08/2005
• Est. Priority Date: 03/06/2004
• Status: Active Grant

• Current Assignee: Kehaai Incorporated
• Original Assignee: Calisto Medical, Inc.
• Inventors: Hambardzumyan, Minas, Farmanyan, Gagik, Malkin, Maksim, Mouradian, Vahram, Armenakyan, Valeri
• Granted Patent: US 7,395,104 B2
• Time in Patent Office: Days
• US Class Current: 600/365
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement

Abstract

Disclosed are systems and methods of determining the amount of a substance in a living organism. In one embodiment, the method comprises: applying an electrical signature signal to the living organism, wherein the electrical signature signal corresponds to a predetermined amount of the substance; measuring the response of the living organism to the applied signature signal; and determining whether an elevated response has resulted from applying the electrical signature signal, if so, then determining the amount of the substance in the living organism from the predetermined amount of the substance.

Claims

1. A method for determining the amount of glucose in a human body, the method comprising:

(a) providing a plurality of electrical signature signals, wherein each electrical signature signal corresponds to a predetermined indicator of glucose.

(b) applying an electrical signature signal from the plurality of electrical signals to at least two electrodes,

(c) measure a first change in impedance over time resulting from the application of the electrical signature signal to produce a first set of measured data;

(d) applying the electrical signature signal from the plurality of electrical signals to the two electrodes

(e) measure a second change in impedance over time resulting from the application of the second electrical signature signal to produce a second set of measured data

(f) determining whether the first set of measure data and the second set of measured data have converged, if yes, then storing the first set and second set as a candidate data set;

(g) determining whether all of the electrical signature signals in the plurality of electrical signature signals have been applied,

if no, then selecting a new electrical signature signal and repeating steps (b) through (g);

if yes, then;

selecting the candidate set having a maximum level of convergence, and

determining the amount of substance from the electrical signature signal producing the selected candidate set.

2. The method of claim 1, further comprising:

measuring the electrical impedance between the electrodes to obtain a signal indicating the electrical impedance,

amplifying the signal indicating the electrical impedance,

determining whether the amplified signal is within a predetermined criteria, if not, then;

calculating a gain factor,

adjusting an amplifier using the gain factor; and

re-measuring the electrical impedance between the electrodes to obtain a signal indicating the electrical impedance.

3. The method of claim 1 further comprising clearing residual voltage between the at least two electrodes.

7. The method of claim 5, wherein the method of claim 1 is repeated for each electrical signature signal in the plurality of electrical signature signals.

4. A method of determining a substance in a living organism, the method comprising:

applying an electrical signature signal to the living organism, wherein the electrical signature signal corresponds to a predetermined amount of the substance;

measuring the response of the living organism to the applied electrical signature signal; and

determining whether an elevated response has resulted from applying the electrical signature signal, if so, then determining the amount of the substance in the living organism from the predetermined amount of the substance.

5. The method of claim 4, further comprising providing a plurality of electrical signal signals, wherein each electrical signature signal in the plurality of electrical signature signals corresponds to a different predetermined amount of the substance.

6. The method of claim 5, wherein the plurality of electrical signature signals correspond to a predetermined amount of the substance ranging from a low amount of the substance to a high amount of the substance.

8. The method of claim 4, wherein the substance is glucose.

9. The method of claim 4, wherein the measuring the response comprises measuring the impedance between two different points on a skin of the living organism.

10. The method of claims 4, wherein the measuring the response comprises:

measuring a plurality of impedance values over time resulting from applying the electrical signature signal corresponding to a predetermined amount of the substance to establish a first data set of measure data values;

reapplying the electrical signature signal to the living organism; and

measuring a plurality of impedance values over time resulting from applying the electrical signature signal to establish a second data set of measure data values.

11. The method of claim 9, further comprising clearing any residual charges between the points on the skin.

12. The method of claim 10, wherein the determining comprises:

determining whether there is convergence between the first and second data sets;

if there is convergence between the first and second data sets, then storing the data sets as a candidate set.

13. The method of claim 12, further comprising:

examining each stored candidate set to determine the candidate set having the largest convergence, and

determining the amount of the substance to be the electric signature signal that corresponds to the candidate set having the largest convergence.

14. A apparatus for measuring a substance in a living organism, the apparatus comprising:

a processor in communication with at least one memory device;

a memory device in communication with the processor, wherein the memory device includes a database of electrical signature signals, wherein each electrical signature signal corresponds to different amounts of the substance in the living organism;

an impedance meter in communication with the processor;

at least two electrodes coupled to the impedance meter such that the impedance meter can measure the impedance between the at least two electrodes, wherein the at least two electrodes are also coupled to the memory device;

a signal amplifier in communication with the processor and the impedance meter, wherein the signal amplifier is adapted to amplify signals from the impedance meter;

an analog-to-digital converter in communication with the amplifier and the processor, wherein the analog-to-digital converter is adapted to convert analog signals from the amplifier to digital signals before sending the digital signals to the processor;

a reset circuit in communication with the processor and coupled to the at least two electrodes.

15. The apparatus of claim 14, wherein the impedance meter further comprises:

an impedance indicator circuit for producing a voltage representing the impedance between the at least two electrodes;

an amplifier in communication with the impedance indicator circuit, wherein the amplifier is adapted to amplify the voltage from the impedance indicator circuit; and

an analog-to-digital converter in communication with the amplifier and the processor, wherein the analog-to-digital converter is adapted for converting analog signals from the amplifier to digital signals.

16. The apparatus of claim 14, wherein the reset circuit is adapted to discharge residual voltage between the at least two electrodes.

17. The apparatus of claim 14, wherein the reset circuit is adapted to change the polarity of the at least two electrodes.

18. The apparatus of claim 14, further comprising a housing which partially surrounds the processor, wherein the housing is adapted for engagement with a strap means such that the apparatus may be worn on a wrist.

19. The apparatus of claim 14, wherein the at least two electrodes are made in part from the group consisting of copper, gold, silver, metal and stainless steel.

20. The apparatus of claim 14, further comprising a user interface, wherein the user interface comprises a touch screen and a flat screen display.